I wrapped my intake runners and airbox with....

[Maleficio]

....black Gorilla brand duct tape to try to reduce heat soaking of the air into the intake.

The other day was fairly cool in relation to the average temps lately, and the car ran very strong. Next day, ambient temps hit 95 or so, the car ran poorly, or not as well as the previous day. That told me the car was suffering from heat soak of the intake plumbing.

I went to a couple of parts houses and couldn't find any sort of heat-resistive tape to use, so I opted for the Gorilla duct tape, which is extremely heavy duty, and black.

Wrapped the runners, taped the inside of the airbox, taped the outside of the airbox, top and bottom, reinstalled, now the car consistently runs like it did on the cool day: very strongly.

This wasn't my idea, I read about someone doing it on Rennlist. They used DEI tape (which I couldn't find in town, I may order some).

I would very much like to wrap the exhaust headers, too. Is it possible to do this without removing the engine? Is there enough clearance to get my hands up in there to wrap the pipes?

By the way, the duct tape looks like crap. It wasn't flexible enough to wrap smoothly around the runners in the tapered sections, but it still improved performance, and gave me a solid direction to work.

[dcrasta]

Yarr Duct Tape...

[Mrmerlin]

if there is any tape or anything else under the aircleaner and on the inside of the aircleaner housing i would suggest that you remove it so it wont get sucked into the cylinders

[Maleficio]

Originally Posted by Mrmerlin

if there is any tape or anything else under the aircleaner and on the inside of the aircleaner housing i would suggest that you remove it so it wont get sucked into the cylinders

Good suggestion. Thanks. I'll remove it and just double up on the external tape.

[Danglerb]

Last time I tried that Gorilla tape didn't come off very easily.

[Mrmerlin]

if it does come off it would suck to have to pull the heads for a valve job ,
or if the tape jammed the throttle open when you didnt want it to be,
could cause an accident

[DPW928]

Porsche designed the 928 with a 17 quart cooling system and 8.5 quart oil system so this wouldn't happen. I see no harm in wrapping the intakes but it appears to be treating the symptoms rather than looking for the source/cause of the heat soak. There could be restrictions in the radiator fins, the mechanical or electrical fan may be bad, the temp sensor(s) may have failed or the engine is running too lean. My guess would be a lean A/F mixture. This can cause excess heat in the combustion chamber which radiates out to the intake and exhaust.

[Maleficio]

Fans work great. I will enrich the mixture tomorrow and see if it helps. Thanks.

[dcrasta]

I was thinking of using some 'pipe insulation' form home depot on the intake tubes..

[Danglerb]

The air coming off the radiator is about 165F last I checked, so doing something to insulate the intake has merit, just not with duct tape.

My wife's Lincoln has OBDII, which means I can plug a cable in under the dash and monitor every sensor in the car real time on a laptop. I was troubleshooting an idle issue, and without a clue what to check looked at everything I could think of, which included the charge air temperature. I could not believe how high it was at an idle, like 145F, so I went out and replaced the sensor with a new one, same temp. Turns out that is normal for idle air flow, but temp drops to about 5F over outside air temps at WOT, which is the only time it really counts anyway.

Before getting too crazy with the intake insulation, it would be worthwhile to stick in a thermocouple and see what the temp is at cruise and above throttle openings, it might be fine already.

[Danglerb]

Originally Posted by dcrasta

I was thinking of using some 'pipe insulation' form home depot on the intake tubes..

I used that on my radiator electric fan, not good, rated temp is right on the edge, and mine has started to deteriorate and bits get blown all over.

[Maleficio]

Yep, duct tape is crude, but it fixed my heat soaked intake problem.

[EIPtuningR32]

you know, they do have thermal header wrap at DAP.... why not use that stuff on everything??

[Maleficio]

I plan on using something like that, I was just broke when I did this.

[Maleficio]

Sorry, I should've said intake tubes, not runners.